OT : M3*0.6mm pitch screws

This is OT, in that they're not going to be used in a classic computer, but people here tinker with other devies too... I am repariign an old French office telephone at the moment, It is missing a number of screws, whih looked to me M3. I therefore (incorrectly) assmed there'd be no problem replacing them. Alas they are not standard M3. After measuring up some of the exisitng screws, they appear to be 3mm in diamter, 0.6mm pitch (standard M3 is 0,5mm pitch). A look in a 1943 Machinery's Handbook suggests this is a French metric thread. Does anyone know of a source of such screws? If I can't get them, I will have to make them I guess (and I think I can get a suitable die which will make life a lot easier), but I'd prefer to buy them. Ideally slotted cheese head, but I would consider just about anything. -tony